tree af40d22af976e945d3d7a542c9a0118680ca68d8
parent d3429987ca895516f93f0fe29618d47949450020
author Jeremy Woods <jbwoods@google.com> 1610403678 -0800
committer Jeremy Woods <jbwoods@google.com> 1610403678 -0800

Add getBackStackEntry that takes a route

There is currently no API to find a NavBackStackEntry using the route.
We should add one to match what we do with destination ids in base
Navigation.

RelNote: "Added a getBackStackEntry API that finds the NavBackStackEntry
using a route."
Test: NavHostControllerTest

Change-Id: If89316ee73218d779dfaa593eeba53a44d9dfb50